GWR withdraw some 800's due to cracks (ORR Report now published)

[fgwrich]

Any chance of a link if they're public please?

From the NIR.

 

[whoosh]

The one thing I note is how often this is made out to be a 'recent' thing affecting new trains. One point I'd like to make is how throughout history there have been build issues with scores of trains!

Steam locos
Mk2 coaches
Class 86s
HSTs
InterCity 225s
Class 150s
Class 158s
Various EMUs
Various other DMUs

Yes, can anyone remember the Sandy derailment of a GNER 225 set? And the rare example of joined up thinking in the privatised world as WAGN's class 365s stepped in to run the services to Leeds, being rapidly route cleared to do so.
All 225s were taken out of service for checks.

 

[Andy Pacer]

8 Hitachi class 800 5 carriage trains have been withdrawn from service due to significant cracks found in the yaw damper bolsters. Not just CAF who appear to have problems with designing/manufacturing vehicles to cope with UK infrastructure.....

Any info as to which units are involved?

 

[X35]

Does anyone have a link to the NIR if applicable?

 

[millemille]

Being a bit pedantic, that's not true actually as there's been no "operational safety cases" since 2006 when ROGS replaced the Safety Case regulations. These days it's Safety Certificates for a Train Operator and in more recent years there's the interface of TOC and ECM to be considered...... both Train Operator and ECM have duties wrt rail vehicles...... albeit usually less complex in TOC-land than in FOC-land as for passenger vehicles the TOC usually performs ECM duties and is deemed competent to meet ROGS Reg 18A duties on the basis they hold a Safety Certificate and the ROGS criteria for Safety Certificate assessment include a chunk on fleet management (ECMs only need to be specifically certified for wagons- the EU Directive extending such certification to locos and non-wagons was NOT adopted into GB law on 1 Jan 2021). The commercial arrangements don't always match up precisely with the regulatory requirements either.......

One of the perennial issues is who can actually raise a NIR under RIS-8250-RST (as in: who has the sort of NIR Online account to do so). Generally only Railway Undertakings and ECMs that can do so- which means that a defect can circulate for a bit in the supply chain before a TOC/FOC realises that there's a defect they have which also meets the criteria for an NIR- and only then does the NIR get raised (yes I do know of examples). Albeit I doubt that applies in this case as it's a much tighter fleet and much closer to the TOC, so looks like it's been raised in good time. My experience with GWR was that they have always been very level-headed with their NIRs so I would expect it's all well under control.

As ever, the check/inspection programme will find the issue, the engineers will work hard on risk assessments to keep as much running (safely!) as possible and the issue will get sorted. I can't really get excited by this, as others have said there's always issues when new vehicles are introduced it's just we're so much better at (a) finding them (b) spreading the word to other operators and (c) putting in place a risk based action plan to manage the situation safely.

TPO

You are absolutely right, my error in not being detailed enough and using lazy colloquial terminology.

Your point about the raising NIR's is a valid one. Part of my role with the 365 fleet was to ensure that the scenario you describe, guilty knowledge (sic) remaining within the supply chain for an unacceptable period, was avoided by dint of being a nosy bugger around the maintenance contractor to ensure that the operator wasn't kept in the dark; deliberately or otherwise.

 

[northernbelle]

Interesting seeing the 'built down to a price' type comments. As others have highlighted, this specific issue has reared its head on a number of other fleets produced by a number of manufacturers - including the well-respected BREL 158/159 fleet that require a more intensive maintenance routine as a result to this very day. In the mid-2010s, the Siemens 332s had to be grounded due to underframe cracking while Bombardier's 220/222 family required modification after a cracked axle and resulting derailment. Neither were show stoppers and resolutions were put in place as with all experience gained from operating trains.

I do wonder (particularly noting 158 and 80x) whether the body flex you get from a long aluminium-bodied vehicle, coupled with lightweight bogies and a more lively ride characteristic, might be a factor.

The AnsaldoBreda heritage is still there !

Given the (so far) affected sets are from the Kasdo/Newton Aycliffe Class 800 build, it's not a factor.

Does anyone have a link to the NIR if applicable?

It's available to authorised users (log in required) - given this I'm surprised to see the detailed content being shared in public.

 

[CBlue]

The one thing I note is how often this is made out to be a 'recent' thing affecting new trains. One point I'd like to make is how throughout history there have been build issues with scores of trains!

Steam locos
Mk2 coaches
Class 86s
HSTs
InterCity 225s
Class 150s
Class 158s
Various EMUs
Various other DMUs

Pretty much this....


Marston cooler groups throwing oil everywhere on HST's springs to mind, and all the overheating woes that caused up until they were re-engined according to a few online sources.
The recent Mk3 coach rebuilds were also a nightmare, partly because of the incredibly slack tolerances used in their production - wide tolerances do not equal good build quality! I've worked in various bits manufacturing long enough to know that.

 

[superkev]

When the 395's were in the design phase the consultancy I was working for at the time was involved, contracted to Hitachi to assist with UK infrastructure interface, and I heard a senior consultant recount that when they'd reviewed the proposed bogie design Hitachi had been told that, while it may be fine for HS1 operation, it would not last when operated on the SE "traditional" routes.

Hitachi reportedly expressed surprise, as they said it was their standard bogie design and it met all of the European standards, but were told in no uncertain terms that it was not robust enough and needed beefing up to cope with UK infrastructure.

In the last week I've heard a consultant who was involved in the CAF 195 design in a similar role recount exactly the same experience....

I've often wondered what's different about UK infrastructure which seems to cause problems with imported kit which works we elsewhere.
I'm old enough to remember the awfull ride of the Swiss SIG bogies on the blue Pullman and initially with the MK4 coaches.
The uk is not immune as the 158s Yaw damper brackets had to be expensivly beefed up prob due to them having the first welded aluminium bodies
K

 

[Wyrleybart]

Pretty much this....


Marston cooler groups throwing oil everywhere on HST's springs to mind, and all the overheating woes that caused up until they were re-engined according to a few online sources.
The recent Mk3 coach rebuilds were also a nightmare, partly because of the incredibly slack tolerances used in their production - wide tolerances do not equal good build quality! I've worked in various bits manufacturing long enough to know that.

Let us not forget that every class 60 required a new three piece drivers side window at each end, simply because the driver was not positioned at the planned original position. Look at any class 60 and compare drivers side to secondmans side cabside windows, where the latter were not replaced.

 

[D7666]

Blue Pullman had Schlieran bogies not SIG.

Both Swiss, but different companies.

 

[Gag Halfrunt]

I've often wondered what's different about UK infrastructure which seems to cause problems with imported kit which works we elsewhere.

Tighter curves?

From the CAF yaw damper thread:

They forgot to specify compliance with infrastructure to GB group standards and not the European interoperability ones. Track geometry in some sidings and turnback locations is more extreme in the GB curvature.

I have suspicion that large rotations with movement near the end of ranges might prove quite interesting.

Dampers can do interesting things near the end of their movement ranges...

 

[superkev]

Blue Pullman had Schlieran bogies not SIG.

Both Swiss, but different companies.

I stand corrected. Jusf remember they were Swiss bogies.
K

 

[py_megapixel]

Hmm... yaw damper failures on cheap-specced new-build units notorious for their awful ride quality.
Where have I heard that one before recently...?

 

[hwl]

Tighter curves?

From the CAF yaw damper thread:

A very different type of failure to the CAF problems and the Hitachi is a lot more solidly built.

The failures are directly above the secondary vertical damper mounting point, the vertical damper is much more likely to generate the cycling stress state need for this fatigue cracks grow. (I'm struggling to understanding how cyclic extending forces on the yaw damper could do that unless it runs out of travel on tight bend a huge number of times)

It might simply be a "manufacturing" issue as the cracks are perpendicular to the main forging direction which is never a great idea.

Similar to the "Heathrow" bolster issues?

 

[Clarence Yard]

The discovery of this fault came about because Hitachi, after learning about the 195/331 issue, bothered to look, even though their units are very different.

They saw a crack in the paintwork on one set and initially thought it was just scoring but thought again, did an NDT, and when the results showed a small but significant crack, they started looking at other units that had paintwork cracks.

As a result, 8 units were stopped by Hitachi over last weekend (6 x 5 car and 2 x 9 car) and all 80x users were sent an urgent technical advice, from which an NIR has appeared.

What happens next, apart from closely checking units on a regular basis, is currently unknown. A rate of deterioration has to be established as well as a method of repair.

 

[millemille]

A very different type of failure to the CAF problems and the Hitachi is a lot more solidly built.

The failures are directly above the secondary vertical damper mounting point, the vertical damper is much more likely to generate the cycling stress state need for this fatigue cracks grow. (I'm struggling to understanding how cyclic extending forces on the yaw damper could do that unless it runs out of travel on tight bend a huge number of times)

Bogie rotational velocity/acceleration is greater than anticipated? Maybe when transitioning from plain line to curved? Or maybe primary suspension bushes are stiffer in yaw than intended so axle movement relative to bogie is reduced and bogie movement relative to body is increased?

Damping is velocity sensitive, not displacement, so unless as you suggest the yaw damper is stroking out then it suggests it's a velocity issue if it stemming from the yaw damper itself...

 

[Hadders]

What chance of 365s coming out of storage and running to Leeds and York....

 

[Nym]

What chance of 365s coming out of storage and running to Leeds and York....

Zero.

 

[Domh245]

The discovery of this fault came about because Hitachi, after learning about the 195/331 issue, bothered to look, even though their units are very different.

They saw a crack in the paintwork on one set and initially thought it was just scoring but thought again, did an NDT, and when the results showed a small but significant crack, they started looking at other units that had paintwork cracks.

Sounds like a good system working! I did note this morning a 700 with what looked like a patch of dust scrubbed away from around the bogie - presumably most manufacturers are checking their units now!

 

[hwl]

Bogie rotational velocity/acceleration is greater than anticipated? Maybe when transitioning from plain line to curved? Or maybe primary suspension bushes are stiffer in yaw than intended so axle movement relative to bogie is reduced and bogie movement relative to body is increased?

Damping is velocity sensitive, not displacement, so unless as you suggest the yaw damper is stroking out then it suggests it's a velocity issue if it stemming from the yaw damper itself...

The dampers are primarily designed to reduce rotational movement and the speed of rotational oscillation at higher train speeds when there shouldn't generally be large displacements as the track curvature can't be that large at those speeds. Which then leaves sudden changes in track curvature e.g. plain line to curved (and v/v) or low speed movements with large displacements.

The 80x also have the lateral coupling dampers that could exerting reasonable sized forces under the conditions above to aid crack growth.

 

[greyman42]

I'd laugh if LNER had to put every available 225 back in service to cover!

Is there any spare HST sets available?

 

[hexagon789]

Yes, can anyone remember the Sandy derailment of a GNER 225 set? And the rare example of joined up thinking in the privatised world as WAGN's class 365s stepped in to run the services to Leeds, being rapidly route cleared to do so.
All 225s were taken out of service for checks.

Vaguely, Great Heck sticks in the mind more so.

Pretty much this....


Marston cooler groups throwing oil everywhere on HST's springs to mind, and all the overheating woes that caused up until they were re-engined according to a few online sources.
The recent Mk3 coach rebuilds were also a nightmare, partly because of the incredibly slack tolerances used in their production - wide tolerances do not equal good build quality! I've worked in various bits manufacturing long enough to know that.

They were built Banana shaped, quite literally, to simplify assembly on the jigs by allowing for hogging when fitting up. Unfortunately it seemed to lead to wide ranging tolerance issues with doors and other fittings.

The cooling issues are I think the main one everyone remembers though, the problems that caused for a few summers in the early 1980s. Then you also had the problems with dual sourcing the traction motors etc etc

Again, as I said these sorts of issues on different levels but with various mechanical elements in train running gear and means of propulsion are simply something which you can trace to several types of trains through history.

Is there any spare HST sets available?

Plenty in store, but I'd imagine competence has completely gone, at least with 225 sets LNER still has some crew passed to work them.

 

[Horizon22]

The BBC has got wind of this now. 6+6-4 = 8 trains.

High-speed GWR trains withdrawn over crack fears

Cracks were discovered during routine maintenance of two Hitachi 800 trains.

www.bbc.co.uk

Six trains, part of a new high-speed fleet, have been taken out of service after hairline cracks were discovered.

Great Western Railway (GWR) said the cracks were found during routine maintenance of two of its Hitachi 800 trains.

It said "possible issues" had been discovered on another six trains, which had been withdrawn from service while investigation work was carried out.

Their withdrawal had no impact on passenger services.

GWR said the hairline cracks were "in areas where the suspension system attaches to the vehicle body on two trains".

 

[RobShipway]

Are the yaw dampers from the same manufacturer for the different trains where there has been an issue with them or are they specifically made by the train manufacturer?

 

[bengley]

There's nothing wrong with the yaw dampers. The problem is the bodyshell of the train where they're mounted.

 

[PHILIPE]

There is a five page thread here regarding the latest developments

www.railforums.co.uk/threads/entire-800-801-802-fleet-stood-down-for-safety-checks.217119/page-5#post-5122269

 

[pcrail]

That yaw damper is a notorious problem area – either the bracket cracks or if the bracket is strong enough, the carbody starts to crack. The issue is quite common with new designs, not only in UK.
A good idea is to keep the bracket itself quite flexible like this one shown below.The ride quallity can be bad if the yaw damper is too steep since it starts to transmit vertical forces from track irregularities to the carbody.

 

[gallafent]

The ride quallity can be bad if the yaw damper is too steep since it starts to transmit vertical forces from track irregularities to the carbody.

That's interesting … I took a look at some pictures of class 80x bogies, and the yaw damper on these seems to be very close to horizontal, in fact, so their poor ride quality must have some other cause(s)!

 

[pcrail]

... the yaw damper on these seems to be very close to horizontal, in fact, so their poor ride quality must have some other cause(s)!

Maybe, it's still coming from the yaw damper. Had the first time a close look on a 800. The bracket is very long in vertical direction. So this lever may still be able to transmit vertical forces in the carbody, just by acting as a lever converting horizontal forces into vertical forces.

 

[Irascible]

Maybe, it's still coming from the yaw damper. Had the first time a close look on a 800. The bracket is very long in vertical direction. So this lever may still be able to transmit vertical forces in the carbody, just by acting as a lever converting horizontal forces into vertical forces.

If it's too long you might get some interesting lateral loads when the body is rolling, too...